36 | About the Radio
Aprisa SRx User Manual 1.3.0
5.
Ethernet Data and Management Priority and Background Bulk Data Transfer Rate
Alternatively to VLAN priority, users can control the Ethernet traffic priority (vs serial), management
priority and rate in order to control the traffic load of the radio network, where important and high
priority data (SCADA) will pass-through first assuring SCADA network operation. The user can set the use of
the Ethernet Data Priority, which controls the priority of the Ethernet customer traffic relative to the
serial customer traffic and can be set to one of the four queues. The Ethernet Management Priority
controls the priority of the Ethernet management traffic relative to Ethernet customer traffic and can be
set to one of the four queues. The Background Bulk Data Transfer Rate sets the data transfer rate (high,
medium, low) for large amounts of management data.
6.
Ethernet Packet Time to Live
Another aspect of avoiding overload radio network is the Ethernet packet TTL, which is used to prevent
old, redundant packets being transmitted through the radio network. This sets the time an Ethernet
packet is allowed to live in the system before being dropped if it cannot be transmitted over the air.
7.
Robust Header Compression (ROHC) and Payload Compression
Aprisa SR supports ROHC (Robust Header Compression RFC3095). ROHC is a standard way to compress IP,
UDP and TCP headers and this significantly increases IP traffic throughput especially in narrow band
network.
Aprisa SR supports payload compression. A Lempel–Ziv (LZ) algorithm is used to efficiently compress up to
50% traffic with high percentage of repetitive strings. Both serial and Ethernet / IP payload traffic are
compressed.
